In March and April of 1944 the USN authorized the augmenting of the AA armament for sixteen units of the original BENSON-GLEAVES group of destroyers operating in the Mediterranean during the Italy campaign as a counter to increased German Air attacks on Allied shipping. The result was an unique configuration that lasted for less than a year and is seldom seen in photos. The most noticeable feature was a platform for four 20-mm guns installed in place of the aft torpedo tubes. Less noticeable was the installation of two single Mk III 40-mm guns.

I suggested to Steve to make a 3-D printed version of this platform with four 20-mm ready service ammo lockers for use on BENSON-GLEAVES class units and ordered one for a project I have to model one of the GLEAVES class units that had this platform installed by altering one of the DML BENSON-GLEAVES class 1/350 scale kits. Below are two images showing where this platform goes.

I'm very pleased with the item and recommend it for anyone interested in modeling this unique configuration. Depending on which DML BENSON-GLEAVES class kit you use, some fitting will be required. The platform was simply installed over the foundation of the removed aft Torpedo Tube mount. In the photos it isn't clear exactly the interface connection that the platform had with the ship. It looks to me the the platform "deck" was more or less even with the midships deckhouse once installed. I decided to install the platform as seen above. Support stanchions, two per side, were installed along the deck edge to support the platform. See attached images below.

As for some background as to which BENSON-GLEAVES units had this unique armament configuration.

After the Anzio Landings the German attacks of Allied ships started to be more effective with new weapons and tactics being used. One of the countermeasures implemented by the USN was to augment temporarily the anti-aircraft armament of destroyers and destroyer escorts assigned to duty in the Med with more 20-mm and single hand-operated 40-mm guns.

For sixteen units of the original group of BENSON-GLEAVES class units (DD-421 through 443) assigned to four Destroyer Divisions, DesDiv 13, 14, 21, and 25), four extra 20-mm and two US Army type single 40-mm guns (Mk III) were authorized for installation in March and April 1944. The Repeat BENSON-GLEAVES classes had seven 20-mm guns already, compared to the four 20-mm guns of the original BENSON-GLEAVES units, and were considered to not need additional weapons.

The four extra 20-mm guns were installed on a temporary platform that replaced the aft torpedo tubes. Whereas the two single 40-mm guns were installed on the main deck amidships between the twin 40-mm mounts and the 20-mm platform, one per side. A very poor location with limited firing arc. But, did provide additional 40-mm fire at low-altitude targets like German torpedo bombers.

Of the sixteen units, at least seven and maybe as many as eight units had the additional 20-mm and 40-mm guns installed in theater at Oran by USS VULCAN (AR-5). The remaining units had the additional armament installed at New York Navy Yard.

While in this configuration, USS LANSDALE was attacked by German aircraft less than two weeks after USS VULCAN installed the added armament at Oran. During the attack on her, LANSDALE shot-down two attacking German aircraft. The platform and single 40-mm guns were removed and the aft torpedo tubes reinstalled in late 1944 and early 1945 from the remaining units as they returned for yard periods and as the German aircraft threat diminished in the Med following the Southern France invasion and allied advance in Italy

Below are a couple of the few available overhead images that show this augmented armament.

On USS NIBLACK (DD-424), on 9 April 1944, the single 40-mm guns can just be made out on the main deck between the platform and the twin 40-mm mounts.

On USS MAYO (DD-422), on 15 August 1944 after her Battle damage from February 1944 has been repaired, the single 40-mm guns have not yet been installed, but the K-Guns formerly in these locations have been relocated further aft, just forward of the twin 40-mm mount platforms.

In this close-crop view of USS GLEAVES at NYNY, the support stanchions, relocated K-Gun, and single 40-mm locations can be seen.